1. Field of the Invention
The present invention relates to a fuel cell, and more particularly to a flat-plate type solid electrolyte fuel cell.
2. Description of the Prior Art
A solid electrolyte type fuel cell is constituted by arranging a number of cell members wherein electrode portions are formed and electrically connecting those cell members.
A fuel cell as shown in FIG. 1 is pointed out as having flat-plate cell members among cell members in the prior art solid electrolyte type fuel cells.
Cell member 44 comprises flat-plate solid electrolyte 41, flat-plate air electrode 42 formed on one side of flat-plate solid electrolyte 41 and fuel electrode 43 formed on the other side of flat-plate solid electrolyte 41. Distributers 45 are mounted on both of the surfaces of the electrode of the cell member 44. Each of distributers 45 is made of gas-permeable, electrically conductive, atmosphere proof and cushioning metallic foam, ceramic felt, ceramic foam and the like. Interconnectors 46 are positioned on both of the outer surfaces of distributers 45 so that interconnectors 46 can push distributers 46 to the surfaces of the electrodes. This electrode member 44, distributers 45 and interconnectors 46 constitute a unit and a number of units are stacked up in multiple layers. An electric circuit is constituted by connecting the most outer interconnectors. Space formed by air electrode 42 and interconnector 46 makes an air path, through which air is supplied. An O ring is put into the space formed by fuel electrode 43 and interconnector 46, thereby a fuel path being formed. Fuel is supplied into said fuel path.
There, however, have been the following problems in the solid electrolyte type fuel cell, for which said prior art flat-plate cell member was used:
(1) Since strength of the cell member itself is small, even though a foaming material and a felt material play a role of a cushion, the cell member can break when the cell members are stacked up in multiple layers.
(2) For the same reason as mentioned above, a cell member of a large area is hard to manufacture.
(3) A creep deformation and the like can be produced by a long time contact with a foaming material and a felt material and the electrode member deteriorates.